Please give the answer quickly in my I.d address. Can a man do marriage with his mother in law after divorce of her daughter?
This is even then haram if his wife died because of the Verse from surat an-Nisa (4:23) which clearly mention
Prohibited to you [for marriage] are ..., your wives' mothers ...
among those who are haram to marry (even if he didn't have intercourse with his former wife)! Under mothers we understand the mother in law and the grandmother of the (former) wife etc.
And Allah knows best